1. Field of the Invention
The field of this invention relates to flashlights and other hand holdable type of illumination apparatuses.
2. Description of the Prior Art
The concept of this invention is being discussed in relation to a lantern. However, it is considered to be within the scope of this invention that the term lantern is to include a flashlight, a lamp or any other type of hand holdable by a human being, illumination device.
Lanterns are in exceedingly common use. The typical construction for a lantern would be a housing within which is incorporated a battery source and a light bulb. A manually operated switch is included within the circuit between the battery and the light bulb. Turning on the switch causes the light bulb to be illuminated. Turning off of the switch causes the light bulb to not be illuminated.
Within certain environments, it is desirable to make sure that the lantern will always operate. One of these environments would be underwater, in other words during scuba diving. The user of the lantern can be in a close-quartered underwater environment and if the lantern goes out, that can place the individual in extreme danger. Therefore, in certain instances, there is a need to incorporate a reserve power arrangement in conjunction with the lantern.
Within the prior art there are numerous multi-battery powered flashlights. However, all such flashlights are known to have a single usable power source that provide for replacement or for recharging when necessary upon battery failure.